Adhesive composition for optical device and adhering method using the same

Abstract

This invention relates to an adhesive composition for an optical device, including pigment balls having a core-shell structure, a thermocurable monomer or oligomer, a photocurable monomer or oligomer, a photoinitiator and a thermal initiator, and to a method of adhering an optical device using the adhesive composition. The adhesive for an optical device according to this invention can improve light shielding and photocuring properties.

What is claimed is: 
     
         1 . An adhesive composition for an optical device, comprising:
 pigment balls having a core-shell structure;   a thermocurable monomer or oligomer;   a photocurable monomer or oligomer;   a photoinitiator; and   a thermal initiator.   
     
     
         2 . The adhesive composition of  claim 1 , comprising 0.01˜5 wt % of the pigment balls, 30˜70 wt % of the thermocurable monomer or oligomer, 20˜60 wt % of the photocurable monomer or oligomer, 0.1˜10 wt % of the photoinitiator and 0.1˜10 wt % of the thermal initiator. 
     
     
         3 . The adhesive composition of  claim 1 , wherein the pigment balls are configured to have a core comprising a pigment and a shell comprising a thermocurable monomer or oligomer, a core comprising a thermocurable monomer or oligomer and a shell comprising a pigment, or a mixture thereof. 
     
     
         4 . The adhesive composition of  claim 1 , wherein the pigment balls comprise 5˜95 wt % of a pigment and 5˜95 wt % of a thermocurable monomer or oligomer. 
     
     
         5 . The adhesive composition of  claim 1 , wherein the pigment balls have an average particle size of 0.5˜5 μm. 
     
     
         6 . The adhesive composition of  claim 2 , wherein the pigment is a carbon- or metal-based pigment comprising one or more selected from the group consisting of carbon (C), titanium (Ti), copper (Cu), iron (Fe), manganese (Mn), silver (Ag), cobalt (Co) and chromium (Cr). 
     
     
         7 . The adhesive composition of  claim 1 , wherein the thermocurable monomer or oligomer includes one or more selected from the group consisting of melamine, a uric acid monomer, bisphenol-A, xylenol, phenol, cresol, alkylphenol and an ethylenically unsaturated monomer having an epoxy group. 
     
     
         8 . The adhesive composition of  claim 2 , wherein the thermocurable monomer or oligomer includes one or more selected from the group consisting of melamine, a uric acid monomer, bisphenol-A, xylenol, phenol, cresol, alkylphenol and an ethylenically unsaturated monomer having an epoxy group. 
     
     
         9 . The adhesive composition of  claim 1 , wherein the photocurable monomer or oligomer includes one or more selected from the group consisting of fumaric acid, maleic acid, maleic anhydride, epoxy acrylate, urethane acrylate, polyester acrylate, a diazonium salt, a diaryliodonium salt and a triarylsulfonium salt. 
     
     
         10 . The adhesive composition of  claim 1 , wherein the photoinitiator includes one or more selected from the group consisting of benzophenone, acetophenone, thioxanthone, an onium salt and a Bronsted-Lewis acid. 
     
     
         11 . The adhesive composition of  claim 1 , wherein the thermal initiator includes one or more selected from the group consisting of carboxylic acid, benzoyl peroxide, azobenzene, and azobisisobutyronitrile (AIBN). 
     
     
         12 . A method of adhering an optical device, comprising:
 applying the adhesive composition of  claim 1  on a substrate having an image sensor attached thereto;   adhering a housing having a lens barrel to the adhesive composition;   photocuring the adhesive composition; and   thermally curing the adhesive composition.   
     
     
         13 . The method of  claim 12 , wherein the photocuring is performed in a wavelength range of 340˜380 nm. 
     
     
         14 . The method of  claim 12 , wherein the thermally curing is performed at 50˜200° C. 
     
     
         15 . The method of  claim 12 , wherein the optical device is an imaging device or an image projection device.